Energy-efficient use of fume cupboards

Results are described from experiments in which time-controller clocks were fitted to some 18 representative, randomly selected fume cupboards in the Chemistry Department of the University College of Wales, Swansea. An average reduction of close to 90% on uncontrolled manual time usage was recorded. This, when translated into the energy savings resulting from the markedly lower electrical fan-power consumptions and mechanically extracted space-heat requirements, revealed that a realistic saving of over £650 per fume cupboard variable cost (1989 prices) per annum could be made in circumstances where, previously, the fume cupboard had been largely (over 90% of the time) left on. The cost of assembling and fitting the controllable equipment (all done on site) was such that the simple payback for the operation may be as short as two months. Realistic savings in excess of £20 000 per annum resulting from this exercise are estimated. This exercise has been part of a programme of energy-cost reductions at the University College over the last few years that have proven savings of approximately £100 000 out of a budget of £750 000.